The present invention relates to electrical connector assemblies. More particularly, certain embodiments of the present invention relate to connector assemblies that include receptacle housings having integrally formed dielectric covers, and having stamped contacts and inner shields.
In the past, connectors have been proposed for interconnecting coaxial cables. Generally, coaxial cables have a circular geometry formed with a central conductor (of one or more conductive wires) surrounded by a dielectric material. The dielectric material is surrounded by a cable braid (of one or more conductive wires) that serves as a ground, and the cable braid is surrounded by a cable jacket. In most coaxial cable applications, it is preferable to match the impedance between source and destination electrical components located at opposite ends of the coaxial cable. When sections of coaxial cable are interconnected by connector assemblies, it is equally preferable that the impedance remain matched through the interconnection.
Today, coaxial cables are widely used. Recently, demand has arisen for radio frequency (RF) coaxial cables in applications such as the automotive industry. The demand for RF coaxial cables in the automotive industry is due in part to the increased number of signals carried within automobiles, such as AM/FM radios, cellular phones, GPS, satellite radios, Blue Tooth(trademark) compatible systems and the like.
Conventional coaxial connectors include diecast or screw machined outer shells, molded or screw machined dielectric housings and screw machined or drawn center contacts. The center contact is terminated to the center conductor of the coaxial cable. The center conductor is slid through an opening in the outer shell until seated. A ferrule is then slid into place and crimped thereby providing a ground path.
Some connector assemblies include matable plug and receptacle housings carrying separate dielectric subassemblies. The dielectric subassemblies include dielectric members, metal outer shields, and center contacts. The dielectric subassemblies receive and retain coaxial cable ends, and the outer shields have pins that pierce the jacket of the cable to electrically contact the cable braids while the center contacts engage the central conductors. The plug and receptacle housings include interior latches that catch and hold the dielectric subassemblies, and thus the coaxial cable ends, therein. When the plug and receptacle housings are mated, the dielectric subassemblies are engaged such that the outer shields are interconnected and the center contacts are interconnected with the dielectric members interconnected therebetween to form a dielectric layer between mated outer shields and mated center contacts.
However, some coaxial connector assemblies suffer from certain drawbacks. The interior latches allow the dielectric subassemblies to axially float forward and backward within the plug and receptacle housings. When the plug and receptacle housings are mated, the dielectric subassemblies have a limited longitudinal clearance in order that the mated dielectric subassemblies separate slightly from each other without being disconnected or interrupting the electrical connection. When such a separation occurs, the dielectric members are slightly separated such that air gaps develop between the connected center contacts and the connected outer shields. Because air has a different dielectric constant than that of the dielectric members and cable dielectric material, the impedance experienced by the electric signals changes at the point where the dielectric subassemblies interconnect. The change in impedance causes the electric signals to be reflected at the point of interconnection, which increases the power required to electrically connect the coaxial cables.
Additionally, typical connector assemblies include many separate components that are screw-machined and die-cast. These processes add additional costs to the assemblies themselves, and to the process of assembling the connector. Further, connector assemblies having circular cross-sectional geometries are difficult to manufacture, and often have tolerances that may produce variations in impedance.
Thus, a need exists for a more efficient and easier-to-assemble electrical connector.
Embodiments of the present invention provide a connector assembly comprising a first housing configured to be mounted to a coaxial cable and a second housing configured to be mounted on a circuit board. The first and second housings mate with one another and at least one of the first and second housings comprises a central contact, a ground shield and a dielectric cover.
The ground shield surrounds at least a portion of the central contact. The dielectric cover holds the central contact and the ground shield. The dielectric cover comprises a contact cavity having an open front end and a closed rear wall. The rear wall comprises a dielectric member formed integral therewith and extending outwardly into the contact cavity to a position between the central contact and the ground shield. The central contact and the ground shield are electrically isolated and separated from one another within the dielectric cover by at least the dielectric member. The dielectric member may extend along at least one complete side of the central contact. The dielectric member of one of the first and second housings is configured to slide along a corresponding dielectric member of the other housing.
The ground shield may include bottom and side panels formed integrally with one another. The bottom panel is positioned below the central contact and the dielectric member is positioned above the central contact. Optionally, the ground shield includes top and side panels formed integrally with one another such that the top panel is positioned above the central contact and the dielectric member is positioned below the central contact.